About resolution and formats

[Krel]

I do not know much about digital formats. I understand the basics of PAL/NTSC, resolution, but there are many formats I do not understand.
How does "aspect ratio" work? (Something about pixel sizes?)
What is "field"?(Upper First, Lower First, Progressive)
Why does "NTSC D1 16:9 Fielded" have a height of 486 while "NTSC DV 16:9" has a height of 480?

I just want to know what setting will be the most flexible for exporting for many different formats. I want my film to be able to take on anything, and HD if possible with my 2Gig ram. I was thinking of creating my film piece by piece as to not overwhelm my computer. Then I would take those scenes are put them together in another program.
What would you recommend?

Any help would be excellent.
Love this program.
-Krel

[malcooning]

these will give you ideas
pixel aspect ratio
Screen aspect ratio
Display resolution
fields

when working HD there are more things to consider than the RAM the main ones are drive speed write/read and single/dual/quad cores.

I want my film to be able to take on anything

what do you mean by that, and why do you want it to take anything?
first I think you should read about, and then decide on your work flow.
This will determine which formats are best for you, and whether your equipment can handle it.